Awareness and Preparedness

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MAYON VOLCANO BULLETIN 31 May 2013 5:00 PM

This serves as notice for the raising of Mayon Volcano’s status from Alert Level 0 (normal) to Alert Level 1 (abnormal).

In the past 36-hr period, three weeks after phreatic explosion on 7 May, visible but weak and short-lived emission of bluish H2S fumes was observed at Mayon Volcano, with persistent crater glow of Intensity I (weak) visibly observed in the evening to early morning. The persistence of weak glow may denote heating of the atmosphere above the crater due to a steady emission of magmatic gas. SO2 measurements for the same period have nonetheless varied between 55 and 388 tonnes/day, and for today averaged 290 tonnes/day, remaining below normal levels of 500 tonnes/day. Seismicity has been markedly low, while recently concluded ground deformation survey by Precise Leveling indicate slight inflation of the edifice compared to February 2013 survey data.

In view of the observation of fumes and visible crater glow, despite most monitoring parameters remaining within baseline levels, PHIVOLCS is raising the alert status of Mayon from Alert Level 0 to Alert Level 1 as a precaution to the public that the volcano is exhibiting abnormal behavior. As before, PHIVOLCS strongly reiterates that the 6-kilometer radius Permanent Danger Zone or PDZ should be a no-entry zone to the public because of the perennial danger of life-threatening rockfalls, avalanches, ash puffs and sudden phreatic or steam-driven eruptions. Mayon’s alert level status may further change if significant changes in monitoring parameters occur. PHIVOLCS advises residents around the volcano to remain vigilant and to keep abreast of updates on Mayon’s condition through local and national officials. PHIVOLCS maintains its close monitoring of the volcano and any significant observation will be immediately communicated to all concerned stakeholders.